Microbiological safety of retail vacuum-packed and modified-atmosphere-packed cooked meats at end of shelf life

Microbiological Quality of Cooked Chicken: Results of Monitoring in England (2013-17)

Results from monitoring of the microbiological quality of 2,721 samples of ready-to-eat cooked chicken collected between 2013 to 2017 in England were reviewed: 70% of samples were from retail, catering or manufacture and 30% were imported and collected at English ports. Samples were tested for a range of bacterial pathogens and indicator organisms. Six samples (<1%) had unsatisfactory levels of pathogens which were potentially injurious to health. Neither Salmonella nor Campylobacter were recovered from any sample. Two samples from catering settings contained either an unsatisfactory level of Bacillus cereus (5 x 10 6 CFU/g) or an unsatisfactory level of coagulase positive staphylococci (1.6 x 10 4 CFU/g). Listeria monocytogenes was recovered from 36 samples (one at manufacture, 26 at catering and nine at retail) and in four instances, unsatisfactory levels (≥10 2 CFU/g) were detected (three samples collected at catering and one at retail). For L. monocytogenes there were no significant differences between the rates of contamination with between the samples collected from ports, manufacture, retail supermarkets and other retailers (p = 0.288). There were no differences between the rates of contamination for other potential pathogens detected between samples from different settings. The prevalence of hygiene indicators ( Escherichia coli , Enterobacteriaceae and Aerobic Colony Counts) at import was significantly lower than in samples collected from manufacturers, retail or catering (p < 0.01). Samples collected from catering gave poorer results than all other settings. Regardless of the stage in the food chain, samples from Thailand and from other non-EU countries were of significantly better microbiological quality with respect to indicator organisms than those from the UK or from other EU countries (p = <0.001).

Microbiological Quality of Foodstuffs Sold on Expiry Date at Retail in Portugal: A Preliminary Study

Currently, food waste represents an important issue due to its negative economic, social and environmental impact. To reduce the food waste levels, some retailers’ brands implement discounting based on the proximity to expiry. Since this practice may involve potential food poisoning, a total of 94 food products from animal origin, purchased in two supermarkets in North Portugal on the expiry date, were analyzed for selected foodborne and spoilage microorganisms. Moreover, the samples were classified as satisfactory and not satisfactory according to their microbiological quality. The results showed that none of the samples presented counts for Salmonella spp., S. aureus, B. cereus. L. monocytogenes was detected in one sample over the limit of 2 log cfu/g as defined by Regulation 2073/2005. The evaluation of food hygiene and spoilage indicators showed that the processed foods displayed lower counts than raw products (beef, pork, chicken and fish). Regarding Enterobacteriaceae, raw products presented on average over 2 log cfu/g than processed foods, with the exception of beef samples that accounted over 3 log cfu/g more than processed foods. In addition, E. coli was mainly detected in fresh meat of which chicken and pork displayed the highest counts. Regarding the qualitative classification, 51.06% of the samples were not satisfactory for the total mesophilic counts, while 62.76% and 58.51% displayed positive results for Enterobacteriaceae and molds and yeasts (M&Y) criteria, respectively. In all, 70.21% of the samples analyzed at the expiry date failed, at least, in one microbiological criterion. The results indicate that the foods available at the end of the shelf life in supermarkets do not represent a risk for food poisoning due to the absence of foodborne pathogens. Since the microbiological indicators of storage/handling of raw products were mainly unsatisfactory, this indicates that the sale of these perishable foods at the end of the shelf life may not be recommended. On the other hand, processed products subjected to food conservation procedures (i.e., thermal processing) could be sold at the end of their shelf life or donated beyond the best-before date, due to its physical, chemical and microbiological stability. However, evidences of foodborne outbreaks associated to this kind of foodstuffs indicated the need of a proper risk assessment. Moreover, it is important to remark that other factors such as small sample size, the absence of the evaluation of the handling, and storage conditions along the food chain or organoleptic alterations must be assessed in further studies.

Microbiological Survey of Packaged Ready-to-Eat Red Meats at Retail in New Zealand

A microbiological survey was undertaken on packaged ready-to-eat red meats available at retail in New Zealand. A total of 1,485 samples (297 lots of five samples each) were collected according to a sampling plan based on market share and regulatory regimes (Animal Products Act 1999 and Food Act 1981) and were tested against the microbiological limits specified in Food Standards Code (FSC) 1.6.1 applicable at the time of sampling. Each lot was tested as a composite for the presence or absence of Salmonella spp., coagulase-producing staphylococci, Listeria monocytogenes, and other Listeria spp. at the end of the manufacturer's stated shelf life. Individual samples within a positive lot were subsequently enumerated for L. monocytogenes. None of the samples contained Salmonella spp. or had coagulase-producing staphylococci counts above the acceptable level specified in FSC 1.6.1 (>100 CFU/g). Data showed that 93.6% (278 of 297 lots) of ready-to-eat red meat complied with the FSC 1.6.1 criteria applicable at the time of the survey. The failure of 19 lots (6.4%) was due to the presence of L. monocytogenes from product obtained from 8 of 33 producers tested. Thirteen samples of 95 positive samples were found to contain between 50 and 500 CFU/g L. monocytogenes, but all of these samples were manufactured by the same operator. Pulsed-field gel electrophoresis typing of all of the L. monocytogenes isolates obtained from the survey identified 12 different pulsotypes. Different pulsotypes were often identified in samples from the same operator sampled on separate occasions. A total of 46 lots (15.5%) contained Listeria spp. (including L. monocytogenes). The detection of Listeria in samples may highlight the existence of problems in operator processing and/or packaging processes and suggests that improvements in good hygienic practice and implementation of more effective risk mitigation strategies are needed.

Formulation and Shelf-life of Fish Burgers Served to Preschool Children

Consumer is very careful about healthiness; in this context nutritionists often highlight the importance of fish for human nutrition because of their protein and fatty acid composition. In order to stimulate utilisation and consumption of fish species by unusual target groups such as children, the aim of this research was to formulate and to evaluate shelf-life and nutritional values of fish preparations stored in modified atmosphere packaging (MAP). Fish species used for trail were Trachurus trachurus and Oncorhynchus mykiss fished and farmed in Basilicata region respectively. Fish burgers were made with different ingredients of plant and animal origin and packed in air (control) and in MAP and stored at refrigeration atemperature. Sensory, physical-chemical analysis as pH, a_w, total volatile nitrogen (TVN), trimetilammine (TMA), thiobarbituric acid (TBA), free fatty acids (FFA) and microbiological analysis like aerobic plate count, Enterobacteriaceae, Escherichia coli, Pseudomonas spp., sulphite-reducing clostridia, Staphylococci, Salmonella spp. and Listeria monocytogenes were performed at intervals of 0°, 1°, 2°, 5°, 8°, 15°, 22°, day from production. Results showed that fish burgers stored in MAP had a longer shelf-life; protein degradation indexes and spoilage bacterial species showed lower values in the samples packaged in MAP compared with the control. The formulation of the fish burger meets the approval of the target consumers. The mixing of natural ingredients has made possible both the enhancement of the organoleptic characteristics with an excellent balance of nutritional values. The diversification of fish preparations, besides enhancing the fish production of marginal areas would add value to a product with potential and remarkable profit margins.

Variation in the microbiological quality of commercially produced vacuum-packed cooked sliced meat between production and the end of shelf-life

A study of the microbiological quality of cooked, sliced vacuum-packed meat was undertaken. Three hundred and eighty-one samples were taken (127 sets of three samples) from 55 commercial premises that produced packets of sliced, cooked, vacuum-packed meat for retail sale. The set of three samples consisted of one from the unsliced, cooked meat, one from the sliced product immediately after slicing, and one sliced packet for end of shelf-life testing. Samples were examined for aerobic colony count (ACC), Enterobacteriaceae, Escherichia coli, Listeria, and Salmonella. When compared to current UK guidelines for the quality of ready to eat food, samples were found to be unsatisfactory for ACC, Enterobacteriaceae, and E. coli. Unsatisfactory rates increased at the end of shelf-life compared to the unsliced meat sample results. No samples were positive for Listeria monocytogenes or Salmonella. This data is important for producers setting the shelf-life of their products.

Assessment of hygiene standards and Hazard Analysis Critical Control Points implementation on passenger ships

The level of hygiene on ferries can have impact on travellers' health. The aim of this study was to assess the hygiene standards of ferries in Greece and to investigate whether Hazard Analysis Critical Control Points (HACCP) implementation contributes to the hygiene status and particularly food safety aboard passenger ships. Hygiene inspections on 17 ferries in Greece were performed using a standardized inspection form, with a 135-point scale. Thirty-four water and 17 food samples were collected and analysed. About 65% (11/17) of ferries were scored with >100 points. Ferries with HACCP received higher scores during inspection compared to those without HACCP (p value <0.001). All 34 microbiological water test results were found negative and, from the 17 food samples, only one was found positive for Salmonella spp. Implementation of management systems including HACCP principles can help to raise the level of hygiene aboard passenger ships.

Prevalence and level of Listeria monocytogenes and other Listeria species in selected retail ready-to-eat foods in the United Kingdom

Although listeriosis is a rare cause of human disease in the United Kingdom, an increase in the number of cases has been observed since 2001, almost exclusively in persons older than 60 years. This increase prompted this study on the microbiological safety of ready-to-eat (RTE) foods, which included those types potentially linked to cases of listeriosis. Between May 2006 and April 2007, 6,984 RTE foods were sampled (2,168 sliced meats, 1,242 hard cheese, 1,088 sandwiches, 878 butter, 725 spreadable cheese, 515 confectionery products containing cream, and 368 probiotic drinks). The food types with the highest prevalence of Listeria monocytogenes were sandwiches (7.0%) and sliced meats (3.7% within shelf life, 4.2% end of shelf life). L. monocytogenes at > 100 CFU/g (exceeding the European Commission's food safety criteria limit) only occurred in sandwiches (0.4%) and sliced meats (0.7% within shelf life, 1.0% end of shelf life). Contamination with L. monocytogenes at >100 CFU/g was more frequent in meats that were prepacked and/or of pack size > or = 300 g and in sandwiches that were supplied prepacked that contained salad vegetables as an ingredient. Satisfactory microbiological quality was associated with premises on which the management was trained in food hygiene and those that complied with hazard analysis and critical control point principles. This study provides important information about the microbiological safety of RTE foods and demonstrates that the control of L. monocytogenes in such foods, and in particular sandwiches and sliced meats, is essential in order to minimize the risk of this bacterium being present at levels hazardous to health at the point of consumption.

Precut prepackaged lettuce: a risk for listeriosis?

The most recent outbreaks of listeriosis have been traced back to contaminated ready-to-eat (RTE) poultry and meat products. However, Listeria monocytogenes can be isolated from every food group, including fresh vegetables. This review is focused on one of the most popular RTE vegetable products, precut prepackaged lettuce. The available literature concerning Listeria contamination of vegetables is reviewed, and possible reasons why no recent outbreaks or sporadic cases of listeriosis due to contaminated precut prepackaged lettuce are explored.